As a pneumatic tire, a constitution in which a plurality of circumferential main grooves are formed at a tread surface at intervals in a tire width direction and a tire is partitioned into a plurality of land sections by the circumferential main grooves is known (for example, refer to Patent Document 1).
In the above-described pneumatic tire, a significantly large load (contact pressure) is applied to shoulder land sections of the land sections, which are located at an outermost portion in the tire width direction during high-speed turning and the like. For this reason, in order to improve steering stability during high-speed turning and the like, the rigidity of the shoulder land sections needs to be increased.
Here, for example, when all of the shoulder land sections are configured to have smooth surfaces to increase the rigidity of the shoulder land sections, a distribution of contact pressure easily lacks uniformity, and thus ground contact properties deteriorate.
On the other hand, a plurality of lug grooves extending in a tire width direction being formed at the shoulder land sections at intervals in a tire circumferential direction so that ground contact properties are improved can be conceived.
However, in this case, drainage can be improved, but block segment sections easily collapse and the rigidity of the shoulder land sections decreases. As such, it is difficult to obtain sufficient steering stability.